What is data backup? Explain different types of backup.

Data Backup is the process of creating copies of data to protect against data loss due to hardware failure, malware, accidental deletion, or natural disasters.

Types of Backup:

1. Full Backup — Copies all selected data every time. Most reliable but takes longest time and most storage.
2. Incremental Backup — Copies only data that has changed since the last backup (full or incremental). Fastest but requires all incremental backups for restoration.
3. Differential Backup — Copies all data changed since the last full backup. Faster restoration than incremental, moderate storage requirement.